Reading and Writing Mapdl Archive Files

Reading ANSYS Archives

MAPDL archive *.cdb and *.dat files containing elements (both legacy and modern) can be loaded using Archive and then converted to a vtk object:

from ansys.mapdl import reader as pymapdl_reader
from ansys.mapdl.reader import examples

# Read a sample archive file
archive = pymapdl_reader.Archive(examples.hexarchivefile)

# Print various raw data from cdb
print(archive.nnum, archive.nodes)

# access a vtk unstructured grid from the raw data and plot it
grid = archive.grid
archive.plot(color='w', show_edges=True)

You can also optionally read in any stored parameters within the archive file by enabling the read_parameters parameter.

from ansys.mapdl import reader as pymapdl_reader
archive = pymapdl_reader.Archive('mesh.cdb', read_parameters=True)

# parameters are stored as a dictionary
archive.parameters

See the Archive class documentation below for more details on the class methods and properties.

Writing ANSYS Archives

Unstructured grids generated using VTK can be converted to ANSYS APDL archive files and loaded into any version of ANSYS using pymapdl_reader.save_as_archive. The following example using the built-in archive file demonstrates this capability.

import pyvista as pv
from pyvista import examples
from ansys.mapdl import reader as pymapdl_reader

# load in a vtk unstructured grid
grid = pv.UnstructuredGrid(examples.hexbeamfile)
script_filename = '/tmp/grid.cdb'
pymapdl_reader.save_as_archive(script_filename, grid)

# optionally read in archive in ANSYS and generate cell shape
# quality report
from ansys.mapdl.core import launch_mapdl
mapdl = launch_mapdl()
mapdl.cdread('db', script_filename)
mapdl.prep7()
mapdl.shpp('SUMM')

Resulting ANSYS quality report:

------------------------------------------------------------------------------
           <<<<<<          SHAPE TESTING SUMMARY           >>>>>>
           <<<<<<        FOR ALL SELECTED ELEMENTS         >>>>>>
------------------------------------------------------------------------------
                   --------------------------------------
                   |  Element count        40 SOLID185  |
                   --------------------------------------

 Test                Number tested  Warning count  Error count    Warn+Err %
 ----                -------------  -------------  -----------    ----------
 Aspect Ratio                 40              0             0         0.00 %
 Parallel Deviation           40              0             0         0.00 %
 Maximum Angle                40              0             0         0.00 %
 Jacobian Ratio               40              0             0         0.00 %
 Warping Factor               40              0             0         0.00 %

 Any                          40              0             0         0.00 %
------------------------------------------------------------------------------

Converting a MAPDL Archive File to VTK for Paraview

MAPDL archive files containing solid elements (both legacy and modern) can be loaded using Archive and then converted to a VTK object.

from ansys.mapdl import reader as pymapdl_reader
from ansys.mapdl.reader import examples

# Sample *.cdb
filename = examples.hexarchivefile

# Read ansys archive file
archive = pymapdl_reader.Archive(filename)

# Print overview of data read from cdb
print(archive)

# Create a vtk unstructured grid from the raw data and plot it
grid = archive.parse_vtk(force_linear=True)
grid.plot(color='w', show_edges=True)

# save this as a vtk xml file
grid.save('hex.vtu')

You can then load this vtk file using pyvista or another program that uses VTK.

# Load this from vtk
import pyvista as pv
grid = pv.read('hex.vtk')
grid.plot()

Supported Elements

At the moment, only solid elements are supported by the save_as_archive function, to include:

• vtk.VTK_TETRA

• vtk.VTK_QUADRATIC_TETRA

• vtk.VTK_PYRAMID

• vtk.VTK_QUADRATIC_PYRAMID

• vtk.VTK_WEDGE

• vtk.VTK_QUADRATIC_WEDGE

• vtk.VTK_HEXAHEDRON

• vtk.VTK_QUADRATIC_HEXAHEDRON

Linear element types will be written as SOLID185, quadratic elements will be written as SOLID186, except for quadratic tetrahedrals, which will be written as SOLID187.

Archive Class

class ansys.mapdl.reader.archive.Archive(filename, read_parameters=False, parse_vtk=True, force_linear=False, allowable_types=None, null_unallowed=False, verbose=False, name='', read_eblock=True)

Read a blocked ANSYS archive file or input file.

Reads a blocked CDB file and optionally parses it to a vtk grid. This can be used to read in files written from MAPDL using the CDWRITE command or input files ('.dat') files written from ANSYS Workbench.

Write the archive file using CDWRITE, DB, archive.cdb

Parameters:

• filename (string, pathlib.Path) – Filename of block formatted cdb file

• read_parameters (bool, optional) – Optionally read parameters from the archive file. Default False.

• parse_vtk (bool, optional) – When True, parse the raw data into to VTK format.

• force_linear (bool, optional) – This parser creates quadratic elements if available. Set this to True to always create linear elements. Defaults to False.

• allowable_types (list, optional) –

  Allowable element types. Defaults to all valid element types in ansys.mapdl.reader.elements.valid_types

  See help(ansys.mapdl.reader.elements) for available element types.

• null_unallowed (bool, optional) – Elements types not matching element types will be stored as empty (null) elements. Useful for debug or tracking element numbers. Default False.

• verbose (bool, optional) – Print out each step when reading the archive file. Used for debug purposes and defaults to False.

• name (str, optional) – Internally used parameter used to have a custom __repr__.

• read_eblock (bool, default: True) – Read the element block.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> hex_beam = pymapdl_reader.Archive(examples.hexarchivefile)
>>> print(hex_beam)
ANSYS Archive File HexBeam.cdb
  Number of Nodes:              40
  Number of Elements:           321
  Number of Element Types:      1
  Number of Node Components:    2
  Number of Element Components: 2

Print the node array

>>> hex_beam.nodes
array([[0.  , 0.  , 0.  ],
       [1.  , 0.  , 0.  ],
       [0.25, 0.  , 0.  ],
       ...,
       [0.75, 0.5 , 3.5 ],
       [0.75, 0.5 , 4.  ],
       [0.75, 0.5 , 4.5 ]])

Read an ANSYS workbench input file

>>> my_archive = pymapdl_reader.Archive('C:\Users\user\stuff.dat')

Notes

This class only reads EBLOCK records with SOLID records. For example, the record EBLOCK,19,SOLID,,3588 will be read, but EBLOCK,10,,,3588 will not be read. Generally, MAPDL will only write SOLID records and Mechanical Workbench may write SOLID records. These additional records will be ignored.

property ekey

Element type key

Array containing element type numbers in the first column and the element types (like SURF154) in the second column.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.ekey
array([[  1,  45],
       [  2,  95],
       [  3,  92],
       [ 60, 154]], dtype=int32)

property elem

List of elements containing raw ansys information.

Each element contains 10 items plus the nodes belonging to the element. The first 10 items are:

• FIELD 0 : material reference number

• FIELD 1 : element type number

• FIELD 2 : real constant reference number

• FIELD 3 : section number

• FIELD 4 : element coordinate system

• FIELD 5 : death flag (0 - alive, 1 - dead)

• FIELD 6 : solid model reference

• FIELD 7 : coded shape key

• FIELD 8 : element number

• FIELD 9 : base element number (applicable to reinforcing elements only)

• FIELDS 10 - 30 : The nodes belonging to the element in ANSYS numbering.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.elem
[array([  1,   4,  19,  15,  63,  91, 286, 240,   3,  18,  17,
         16,  81, 276, 267, 258,  62,  90, 285, 239],
 array([  4,   2,   8,  19,  91,  44, 147, 286,   5,   7,  21,
         18, 109, 137, 313, 276,  90,  43, 146, 285],
 array([ 15,  19,  12,  10, 240, 286, 203, 175,  17,  20,  13,
         14, 267, 304, 221, 230, 239, 285, 202, 174],
...

property elem_real_constant

Real constant reference for each element.

Use the data within rlblock and rlblock_num to get the real constant datat for each element.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.elem_real_constant
array([ 1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
        1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
        1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
        ...,
        1,  1,  1,  1,  1,  1,  1,  1,  1,  1, 61, 61, 61, 61,
       61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61,
       61], dtype=int32)

property element_components

Element components for the archive.

Output is a dictionary of element components. Each entry is an array of MAPDL element numbers corresponding to the element component. The keys are element component names.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.element_components
{'ECOMP1 ': array([17, 18, 21, 22, 23, 24, 25, 26, 27, 28, 29,
                   30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40],
                   dtype=int32),
'ECOMP2 ': array([ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
                  14, 15, 16, 17, 18, 19, 20, 23, 24], dtype=int32)}

element_coord_system()

Element coordinate system number

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.element_coord_system
array([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0], dtype=int32)

property enum

ANSYS element numbers.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.enum
array([    1,     2,     3, ...,  9998,  9999, 10000])

property et_id

Element type id (ET) for each element.

property etype

Element type of each element.

This is the ansys element type for each element.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.etype
array([ 45,  45,  45,  45,  45,  45,  45,  45,  45,  45,  45,
        45,  45,  45,  45,  45,  45,  45,  45,  92,  92,  92,
        92,  92,  92,  92,  92,  92,  92,  92,  92,  92,  92,
        ...,
        92,  92,  92,  92,  92, 154, 154, 154, 154, 154, 154,
       154, 154, 154, 154, 154, 154, 154, 154, 154, 154, 154,
       154], dtype=int32)

Notes

Element types are listed below. Please see the APDL Element Reference for more details:

https://www.mm.bme.hu/~gyebro/files/vem/ansys_14_element_reference.pdf

property filename: str

String form of the filename. This property is read-only.

property grid

Return a pyvista.UnstructuredGrid of the archive file.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.grid
UnstructuredGrid (0x7ffa237f08a0)
  N Cells:      40
  N Points:     321
  X Bounds:     0.000e+00, 1.000e+00
  Y Bounds:     0.000e+00, 1.000e+00
  Z Bounds:     0.000e+00, 5.000e+00
  N Arrays:     13

property key_option

Additional key options for element types

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.key_option
{1: [[1, 11]]}

property material_type

Material type index of each element in the archive.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.material_type
array([1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
       1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
       1, 1, 1, 1], dtype=int32)

property n_elem

Number of nodes

property n_node

Number of nodes

property nnum

Array of node numbers.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.nnum
array([    1,     2,     3, ..., 19998, 19999, 20000])

property node_angles

Node angles from the archive file.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.nodes
[[0.   0.   0.  ]
 [0.   0.   0.  ]
 [0.   0.   0.  ]
 ...,
 [0.   0.   0.  ]
 [0.   0.   0.  ]
 [0.   0.   0.  ]]

property node_components

Node components for the archive.

Output is a dictionary of node components. Each entry is an array of MAPDL node numbers corresponding to the node component. The keys are node component names.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.node_components
{'NCOMP2  ': array([  1,   2,   3,   4,   5,   6,   7,   8,
                     14, 15, 16, 17, 18, 19, 20, 21, 43, 44,
                     62, 63, 64, 81, 82, 90, 91, 92, 93, 94,
                     118, 119, 120, 121, 122, 123, 124, 125,
                     126, 137, 147, 148, 149, 150, 151, 152,
                     153, 165, 166, 167, 193, 194, 195, 202,
                     203, 204, 205, 206, 207, 221, 240, 258,
                     267, 268, 276, 277, 278, 285, 286, 287,
                     304, 305, 306, 313, 314, 315, 316
                     ], dtype=int32),
...,
}

property nodes

Array of nodes.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.nodes
[[0.   0.   0.  ]
 [1.   0.   0.  ]
 [0.25 0.   0.  ]
 ...,
 [0.75 0.5  3.5 ]
 [0.75 0.5  4.  ]
 [0.75 0.5  4.5 ]]

property parameters

Parameters stored in the archive file

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile,
                                     read_parameters=True)
>>> archive.parameters
{}

property pathlib_filename: Path

Return the pathlib.Path version of the filename. This property can not be set.

plot(off_screen=None, full_screen=None, screenshot=None, interactive=True, cpos=None, window_size=None, show_bounds=False, show_axes=None, notebook=None, background=None, text='', return_img=False, eye_dome_lighting=False, volume=False, parallel_projection=False, jupyter_backend=None, return_viewer=False, return_cpos=False, jupyter_kwargs=None, theme=None, hidden_line_removal=None, anti_aliasing=None, zoom=None, border=False, border_color='k', border_width=2.0, ssao=False, **kwargs)

Plot a PyVista, numpy, or vtk object.

Parameters:

• var_item (pyvista.DataSet) – See Plotter.add_mesh for all supported types.

• off_screen (bool, optional) – Plots off screen when True. Helpful for saving screenshots without a window popping up. Defaults to the global setting pyvista.OFF_SCREEN.

• full_screen (bool, default: pyvista.plotting.themes.Theme.full_screen) – Opens window in full screen. When enabled, ignores window_size.

• screenshot (str or bool, optional) –

  Saves screenshot to file when enabled. See: Plotter.screenshot(). Default False.

  When True, takes screenshot and returns numpy array of image.

• interactive (bool, default: pyvista.plotting.themes.Theme.interactive) – Allows user to pan and move figure.

• cpos (list, optional) – List of camera position, focal point, and view up.

• window_size (sequence, default: pyvista.plotting.themes.Theme.window_size) – Window size in pixels.

• show_bounds (bool, default: False) – Shows mesh bounds when True.

• show_axes (bool, default: pyvista.plotting.themes._AxesConfig.show) – Shows a vtk axes widget.

• notebook (bool, default: pyvista.plotting.themes.Theme.notebook) – When True, the resulting plot is placed inline a jupyter notebook. Assumes a jupyter console is active.

• background (ColorLike, default: pyvista.plotting.themes.Theme.background) – Color of the background.

• text (str, optional) – Adds text at the bottom of the plot.

• return_img (bool, default: False) – Returns numpy array of the last image rendered.

• eye_dome_lighting (bool, optional) – Enables eye dome lighting.

• volume (bool, default: False) – Use the Plotter.add_volume() method for volume rendering.

• parallel_projection (bool, default: False) – Enable parallel projection.

• jupyter_backend (str, default: pyvista.plotting.themes.Theme.jupyter_backend) –

  Jupyter notebook plotting backend to use. One of the following:

  • 'none' : Do not display in the notebook.

  • 'static' : Display a static figure.

  • 'trame' : Display using trame.

  This can also be set globally with pyvista.set_jupyter_backend().

• return_viewer (bool, default: False) – Return the jupyterlab viewer, scene, or display object when plotting with jupyter notebook.

• return_cpos (bool, default: False) – Return the last camera position from the render window when enabled. Defaults to value in theme settings.

• jupyter_kwargs (dict, optional) – Keyword arguments for the Jupyter notebook plotting backend.

• theme (pyvista.plotting.themes.Theme, optional) – Plot-specific theme.

• hidden_line_removal (bool, default: pyvista.plotting.themes.Theme.hidden_line_removal) – Wireframe geometry will be drawn using hidden line removal if the rendering engine supports it. See Plotter.enable_hidden_line_removal.

• anti_aliasing (str | bool, default: pyvista.plotting.themes.Theme.anti_aliasing) – Enable or disable anti-aliasing. If True, uses "msaa". If False, disables anti_aliasing. If a string, should be either "fxaa" or "ssaa".

• zoom (float, str, optional) – Camera zoom. Either 'tight' or a float. A value greater than 1 is a zoom-in, a value less than 1 is a zoom-out. Must be greater than 0.

• border (bool, default: False) – Draw a border around each render window.

• border_color (ColorLike, default: "k") –

  Either a string, rgb list, or hex color string. For example:

  • color='white'

  • color='w'

  • color=[1.0, 1.0, 1.0]

  • color='#FFFFFF'

• border_width (float, default: 2.0) – Width of the border in pixels when enabled.

• ssao (bool, optional) – Enable surface space ambient occlusion (SSAO). See Plotter.enable_ssao() for more details.

• **kwargs (dict, optional) – See pyvista.Plotter.add_mesh() for additional options.

Returns:

• cpos (list) – List of camera position, focal point, and view up. Returned only when return_cpos=True or set in the default global or plot theme. Not returned when in a jupyter notebook and return_viewer=True.

• image (np.ndarray) – Numpy array of the last image when either return_img=True or screenshot=True is set. Not returned when in a jupyter notebook with return_viewer=True. Optionally contains alpha values. Sized:

  • [Window height x Window width x 3] if the theme sets transparent_background=False.

  • [Window height x Window width x 4] if the theme sets transparent_background=True.

• widget (ipywidgets.Widget) – IPython widget when return_viewer=True.

Examples

Plot a simple sphere while showing its edges.

>>> import pyvista as pv
>>> mesh = pv.Sphere()
>>> mesh.plot(show_edges=True)

Plot a volume mesh. Color by distance from the center of the ImageData. Note volume=True is passed.

>>> import numpy as np
>>> grid = pv.ImageData(
...     dimensions=(32, 32, 32), spacing=(0.5, 0.5, 0.5)
... )
>>> grid['data'] = np.linalg.norm(grid.center - grid.points, axis=1)
>>> grid['data'] = np.abs(grid['data'] - grid['data'].max()) ** 3
>>> grid.plot(volume=True)

property quality

Minimum scaled jacobian cell quality.

Negative values indicate invalid cells while positive values indicate valid cells. Varies between -1 and 1.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.quality
array([1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1.,
       1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1.,
       1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1.])

property rlblock

Real constant data from the RLBLOCK.

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.rlblock
[[0.   , 0.   , 0.   , 0.   , 0.   , 0.   , 0.02 ],
 [0.   , 0.   , 0.   , 0.   , 0.   , 0.   , 0.01 ],
 [0.   , 0.   , 0.   , 0.   , 0.   , 0.   , 0.005],
 [0.   , 0.   , 0.   , 0.   , 0.   , 0.   , 0.005]]

property rlblock_num

Indices from the real constant data

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.rnum
array([60, 61, 62, 63])

save(filename, binary=True, force_linear=False, allowable_types=[], null_unallowed=False)

Save the geometry as a vtk file

Parameters:

• filename (str, pathlib.Path) – Filename of output file. Writer type is inferred from the extension of the filename.

• binary (bool, optional) – If True, write as binary, else ASCII.

• force_linear (bool, optional) – This parser creates quadratic elements if available. Set this to True to always create linear elements. Defaults to False.

• allowable_types (list, optional) –

  Allowable element types. Defaults to all valid element types in ansys.mapdl.reader.elements.valid_types

  See help(ansys.mapdl.reader.elements) for available element types.

• null_unallowed (bool, optional) – Elements types not matching element types will be stored as empty (null) elements. Useful for debug or tracking element numbers. Default False.

Examples

>>> geom.save('mesh.vtk')

Notes

Binary files write much faster than ASCII and have a smaller file size.

property section

Section number

Examples

>>> from ansys.mapdl import reader as pymapdl_reader
>>> from ansys.mapdl.reader import examples
>>> archive = pymapdl_reader.Archive(examples.hexarchivefile)
>>> archive.section
array([1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
       1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
       1, 1], dtype=int32)

property tshape

Tshape of contact elements.

property tshape_key

Dict with the mapping between element type and element shape.

TShape is only applicable to contact elements.